consisting of a series of angular grooves. Figure 1 compares a conventional glass ophthalmic prism to a 3M Press-On Opti
3M Press-OnTM Optics – How To Apply Using Water
for Eye Care Professionals The Fresnel Prism and Lens Co. Email:
[email protected] Web site: www.fresnel-prism.com Phone: 952-496-0432
3M™ Press-On™ Optics 3M Press-On Optics offer eye care professionals the ability to correct several visual disorders in a simple, therapeutic, inexpensive way - sometimes in just one sitting, sparing the patient multiple sessions. This immediate correction is more comfortable and cosmetically appealing without adding any noticeable weight or thickness to the spectacle, nor causing damage. The 3M Press-On Optics system is easy-to-use, inexpensive and quick for creating prismatic and spherical corrections to existing eyewear. By applying a Press-On sphere or prism to the back surface to one or both of the patient’s lenses in its entirety or to a specific region correction is immediate. These economical, easy-to-use optics come in a full range of 17 powers, and are only 1mm thick regardless of the prescription strength.
The Story Behind Fresnel Lenses In 1822, Augustin Fresnel, a French engineer, articulated the principle of Fresnel Optics. The need for a lightweight, yet functional beacon of light for harbor lighthouses was critical. A prism’s angle of refraction depends only upon the angle of the surfaces and the index of refraction of the material of which the prism is made. The angle of refraction is independent of the prism’s thickness.
Figure 1
The 3M Press-On Optic, whose design is based upon the Fresnel Principle, is a thin transparent plastic sheet, with one face consisting of a series of angular grooves. Figure 1 compares a conventional glass ophthalmic prism to a 3M Press-On Optic. This diagram demonstrates how the application of the Fresnel Principle to the Press-On Optic provides a thin, lightweight lens with the comparable power of a thicker conventional ophthalmic prism.
Press-On Prisms are used to correct several ocular motility disorders. The prism pattern displaces the image. The greater the power the higher the degree of displacement. List of conditions: Strabismus (early onset, mild amblyopia, nystagmus, inoperable or incomitant), Diplopia (3rd, 4th and 6th nerve palsies; post-cateract surgery; myasthenia gravis, multiple sclerosis, graves disease), Phorias (symptomatic or decompensated phorias), Other Medical Indications (bed-ridden patients, ankylosing spondylitis other postural deformities)
PRISM
Press-On Aspheric lenses are used for refractive +/- correction. The Press-On lenses are useful for some refractive corrections. Conditions: Diabetes Mellitus, post-cateract surgery, low vision, and accomodative esotropia. ASPHERIC
Press-On Bifocal (D-Segment) lenses are useful for some bifocal refractive corrections. Applications: Sunglasses, reading, computer or safety glasses
Bifocal (D-Segment)
How to Apply Using Water
Press-On™ Optics ASPHERIC PLUS + 0.50 + 1.00 + 1.50 + 2.00 + 2.50 + 3.00 + 3.50 + 4.00
PRISM + 5.00 + 6.00 + 7.00 + 8.00 + 10.00 + 12.00 + 14.00 + 16.00
ASPHERIC MINUS - 1.00 - 2.00 - 3.00 - 4.00 - 5.00 - 6.00 - 7.00
1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 8.00
9.00 10.00 12.00 15.00 20.00 25.00 30.00 35.00 40.00
BIFOCAL - 8.00 - 9.00 - 10.00 - 11.00 - 12.00 - 13.00 - 14.00
Other Uses Recreational, Industrial. Hobby, Sports, Temporary or Long-term Corrections
+1.00 +1.50 +2.00 +2.50
+3.00 +4.00 +5.00 +6.00
